d3 is not available in dependent app

- On moving form devDependency to dependency ember-cli-d3 is throwing error.

```
BuildingCannot read property 'd3' of undefined
TypeError: Cannot read property 'd3' of undefined
    at Class.module.exports.included (/Users/ssomarajapuram/Documents/Workspace/em-tgraph-git/node_modules/ember-cli-d3/index.js:52:30)
```
